Joker can understand not wanting to think. It's why, when he arrive at the menagerie, he stays quit for once when he spots how involved Ginko is in his work. Maybe it all works out for him, too- he's feeling a bit too tired for his usual extroverted personality with all the recent things that have happened. Not just the vampires, but.... everything.

And he didn't even get to listen to Foster be murdered over the radio. What an unfair world.

Still, while he doesn't say anything, he does follow after Ginko at a distance, just watching him to make sure he doesn't... He has no idea. Faint, or anything. Still, with his appearance and clothing preferences, it's likely easy to spot him ghosting along for Ginko.